Italy’s foreign ministry on Tuesday asked the U.S. government for an explanation amid reports that the National Security Agency eavesdropped on its former prime minister’s telephone in 2011.

John Phillips, Washington’s ambassador to Rome, was summoned “for clarification on the media reports that allege Italian leader Silvio Berlusconi and some of his close associates were subjected to wiretapping in 2011,” Italy’s foreign ministry said in a statement on Tuesday.

The American diplomat was expected to meet with Italian officials later in the day to discuss the allegations, Reuters reported, citing an unnamed source in the foreign ministry.

On Monday, secret-spilling group WikiLeaks claimed that the U.S. spy agency eavesdropped on a 2011 telephone call between Mr. Berlusconi — Italy’s prime minister, at the time — and his Israeli counterpart, Benjamin Netanyahu, according to a previously unpublished NSA document that’s classified as “top secret.”

“Israel has reached out to Europe, including Italy, for help in smoothing out the current rift in its relations with the United States,” the document states.

Mr. Berlusconi “promised to put Italy at Israel’s disposal in helping mend the latter’s ties with Washington” in the midst of a dispute between Washington and Jerusalem over Israel’s decision to build 1,600 homes in land contested by Palestine, the dispatch continued.

Mr. Netanyahu defended the decision to build in East Jerusalem and told his Italian counterpart it “was totally in keeping with national policy dating back to the administration of Golda Meir,” and blamed the tiff on an unnamed “government official with poor political sensitivity,” the NSA’s summary stated.

“The objective now, Netanyahu said, is to keep the Palestinians from using this issue as a pretext to block a resumption of talks or to advance unrealistic claims that could risk sinking the peace negotiations altogether. Continuing, he asserted that the tension has only been heightened by the absence of direct contact between himself and the U.S. President.”

Details concerning the 2011 phone call between the Israeli and Italian prime ministers was published by WikiLeaks this week alongside similar NSA documents revealing surveillance operations that targeted various world leaders, including a cable suggesting the U.S. taped a meeting in which U.N. Secretary General Ban Ki-moon and German Chancellor Angela Merkel discussed climate change.

“Today we showed that U.N. Secretary General Ban Ki-moon’s private meetings over how to save the planet from climate change were bugged by a country intent on protecting its largest oil companies,” WikiLeaks founder Julian Assange said in a statement.

“It will be interesting to see the UN’s reaction, because if the Secretary General can be targeted without consequence then everyone from world leader to street sweeper is at risk,” Mr. Assange added.